Part 110

“The first farm we visited was that of Craigentinney, situated about one mile and a half south-east of Edinburgh, of which 260 Scotch acres” (a Scotch acre is one-fourth more than any English acre) “receive a considerable proportion of such sewerage as, under an imperfect system of house-drainage, is at present derived from half the city. The meadows of which it chiefly consists have been put under irrigation at various times, the most recent addition being nearly 50 acres laid out in the course of last year and the year previous, which, lying above the level of the rest, are irrigated by means of a steam-engine. The meadows first laid out are watered by contour channels following the inequalities of the ground, after the fashion commonly adopted in Devonshire; but in the more recent parts the ground is disposed in ‘panes’ of half an acre, served by their respective feeders, a plan which, though somewhat more expensive at the outset, is found preferable in practice. The whole 260 acres take about 44 days to irrigate; the men charged with the duty of shifting the water from one pane to another give to each plot about two hours’ irrigation at a time; and the engine serves its 50 acres in ten days, working day and night, and employing one man at the engine and another to shift the water. The produce of the meadows is sold by auction on the ground, ‘rouped,’ as it is termed, to the cow-feeders of Edinburgh, the purchaser cutting and carrying off all he can during the course of the letting, which extends from about the middle of April to October, when the meadows are shut up, but the irrigation is continued through the winter. The lettings average somewhat over 20_l._ the acre; the highest last year having brought 31_l._, and the lowest 9_l._; these last were of very limited extent, on land recently denuded in laying out the ground, and consequently much below its natural level of productiveness. There are four cuttings in the year, and the collective weight of grass cut in parts was stated at the extraordinary amount of 80 tons the imperial acre. The only cost of maintaining these meadows, except those to which the water is pumped by the engine, consists in the employment of two hands to turn on and off the water, and in the expense of clearing out the channels, which was contracted for last year at 29_l._, and the value of the refuse obtained was considered fully equal to that sum, being applied in manuring parts of the land for a crop of turnips, which with only this dressing in addition to irrigation with the sewage-water presented the most luxuriant appearance. The crop, from present indications, was estimated at from 30 to 40 tons the acre, and was expected to realize 15_s._ the ton sold on the land. From calculations made on the spot we estimated the produce of the meadows during the eight months of cutting at the keep of ten cows per acre, exclusive of the distillery refuse they consume in addition, at a cost of 1_s._ to 1_s._ 6_d._ per head per week. The sea-meadows present a particularly striking example of the effects of the irrigation; these, comprising between 20 and 30 acres skirting the shores between Leith and Musselburgh, were laid down in 1826 at a cost of about 700_l._; the land consisted formerly of a bare sandy tract, yielding almost absolutely nothing; it is now covered with luxuriant vegetation extending close down to high-water mark, and lets at an average of 20_l._ per acre at least. From the above statement it will be seen how enormously profitable has been the application in this case of town refuse in the liquid form; and I have no hesitation in stating that, great as its advantages have been, they might be extended four or five fold by greater dilution of the fluid. Four or five times the extent of land might, I believe, be brought into equally productive cultivation under an improved system of drainage in the city, and a more abundant use of water. Besides these Craigentinney meadows, there are others on this and on the west side of Edinburgh, which we did not visit, similarly laid out, and I believe realizing still larger profits, from their closer proximity to the town, and their lying within the toll-gates.”[67]

Such, then, are said to be the results of a practical application of sewer-water. The preliminary remark of the Board of Health, however, applies somewhat to the statement above given; for we are not told what the _same land_ produced before the liquid manure was applied; nor are we informed as to the peculiar condition and quantity of the land near Craigentinney, and how it differs from the land near London.

The other returns are of liquid manures, of which sewer-water formed no part, and, therefore, require no special notice of them. The following observations are, however, worthy of attention:--

“The cases above detailed furnish some measure of the possible results attainable in cultivation, especially corroborated as they are by others which did not on this occasion come under our personal observation, but one of which I may mention, having recently examined into it, that of Mr. Dickinson, at Willesden, who estimates his yield of Italian rye-grass at from 80 to 100 tons an acre, and gets 8 or 10 cuttings, according to the season; and as there is no peculiar advantage of soil or climate (the former ranging from almost pure sands to cold and tenacious clays, and the latter being inferior to that of a large proportion of England) to prevent the same system being almost universally adopted, they give some idea of the degree to which the productiveness of land may be raised by a judicious appliance of the means within our reach. When it is considered that such results may, in the vicinity of towns and villages, be most effectually brought about by the instant removal of all those matters which, when allowed to remain in them, are among the most fruitful sources of social degradation, disease, and death, one cannot but earnestly desire the furtherance of such measures as will ensure this double result of purifying the town and enriching the country; and as the facts I have stated came at the same time under the notice of the gentleman I mentioned above, under whose able superintendence the arrangements for the water-supply and drainage of several towns are now in course of execution, I trust it will not be long before this most advantageous mode of disposing of the refuse of towns may be brought into practical operation in various parts of the country.

“I have, &c.,

“D. F. FORTESCUE.

“General Board of Health.”

OF THE NEW PLAN OF SEWERAGE.

This branch of the subject hardly forms part of my present inquiry, but, having pointed out the defects of the sewers, it seems but reasonable and right to say a few words on the measures determined upon for their improvement. It is only necessary for me, however, to indicate the principal characteristics of the new, or rather intended, mode of sewerage, as the work may be said to have been but commenced, or hardly commenced in earnest, the Report of Mr. Frank Forster (the engineer) bearing the date of Jan. 30, 1851.

In the carrying out of the engineer’s plan--which from its magnitude, and, in all human probability, from its cost, when completed, would be _national_ in other countries, but is here only _metropolitan_--in the carrying out of this scheme, I say, two remarkable changes will be found. The one is the employment of the power of steam in sewerage; the other is the diversion of the sewage from the current of the Thames. The ultimate uses of this sewage, agriculturally or otherwise, form no part of the present consideration.

I should, however, first enumerate the general principles on which the best authorities have agreed that the London sewers should be constructed so as to ensure a proper disposal of the sewage, for these principles are said to be at the basis of Mr. Forster’s plan.

I condense under the following heads the substance of a mass of Reports, Committee Meetings, Suggestions, Plans, &c.:--

1. The channels, or pipeage, or other means of conveying away house-refuse, should be so made that the removal will be _immediate_, more especially of any refuse or filth capable of suspension in water, since its immediate carrying off, it is said, would leave no time for the generation of miasma.

2. Means should be provided for such disposal of sewage as would prevent its tainting any stream, well, or pool, or, by its stagnation or obstruction, in any way poisoning the atmosphere. And, as a natural and legitimate result, it should be _so collected that it could be applied to the cultivation of the land_ at the most economical rate.

3. In the providing works of deposit or storage in low districts, or “of discharge where the natural outlets are free,” such works should be provided as would not subject any place, or any man’s property, to the risk of inundation, or any other evil consequence; while in the construction of the drainage of the substratum, the works should be at such a depth below the foundation of all buildings that tenements should not be exposed to that continued damage from exhalation and dampness which leads to the dry rot in timber, and to an immature decay of materials and a general unhealthiness.

There are other points insisted upon in many Reports to which I need but allude, such as

(_a._) The channels containing sewage should be of enduring and impermeable material, so as to prevent all soakage.

(_b._) There should be throughout the channels of the subterranean metropolis a fall or inclination which would suffice to prevent the accumulation of any sewage deposit, with its deleterious influence and ultimate costliness.

(_c._) Similar provisions should be used were it but to prevent the creation of the noxious gases which now permeate many houses (especially in the quarters inhabited by the poor) and escape into many streets, courts, and alleys, for until improvements are effected the pent-up sewage and the saturated brickwork of the sewers and older drains must generate such gases.

(_d._) No tidal stream should ever receive a flow of sewage, because then the cause of evil is never absent, for the filth comes back with the tide; and as the Thames water constitutes the grand fount of metropolitan consumption, the water companies, with very trifling exceptions, give us back much of our own excrement, mixed with every conceivable, and sometimes noxious, nastiness, with which we may brew, cook, and wash--and drink, if we can. Filtering remedies but a portion of the evil.

Now it would appear that not one of these requirements, the necessity of which is unquestioned and unquestionable, is fully carried out by the present system of sewerage, and hence the need of some new plan in which the defects may be remedied, and the proper principles carried out.

The instructions given by the Court were to the following effect:--

A. The Thames should be kept free from sewage whatever the state of the tide.

B. There should be intercepting drains to carry off the sewage (so keeping the Thames unsoiled by it) wherever practicable.

C. The sewage should be raised by artificial means into a main channel for removal.

D. The intercepting sewers should be so constructed as to secure the largest amount of effective drainage without artificial appliances.

In preparing his plan, Mr. Forster had the advice and assistance of Mr. Haywood, of the City Court of Sewers.

The metropolis is divided into two portions--“the northern portion of the metropolis,” or rather that portion of the metropolis which is on the north or Middlesex bank of the Thames; and the southern portion, or that which is on the south or Surrey side of the river.

The northern portion is in the new plan considered to “divide itself into two separate areas,” and to these two areas different modes of sewerage are to be applied:

“1. The interception of the drainage of that district, which, from its elevation above the level of the outlet, is capable of having its sewage and rainfall carried off by gravitation.

“2. The interception of the drainage of that district, which, from its low lying position, will require its sewage, and in most localities its rainfall, to be lifted by steam-power to a proper level for discharge.”

The first district runs from Holsden-green (beyond the better-known Kensall-green) in the west, to the Tower Hamlets in the east. Its form is irregular, but not very much so, merely narrowing from Westbourn-green to its western extremity, the country then becoming rural or woodland. Its highest reaches to the north are to Highgate and Stamford-hill. The nearest approach to the south is to a portion of the Strand, between Charing-cross and Drury-lane. Care has evidently been taken to skirt this district, so to speak, by the canals and the railroads. This division of the northern portion is described as “the district for natural drainage.”

The area of this division is about 25-1/6 square miles.

The second division meets the first at the highway separating Kensington-gardens from Bayswater; and runs on, bordering the river, all the way to the West India Dock. Its shape is irregular, but, abating the roundness, presents somewhat of that sort of figure seen in the instrument known as a dumb-bell, the narrowest or hand-part being that between Charing-cross and Drury-lane, skirting the river as its southern bound. At its eastern end this second district widens abruptly, taking in Victoria-park, Stratford, and Bromley.

The area of this division of the northern portion is 16-1/8 square miles.

There are, moreover, two small tracts, comprising the southern part of the Isle of Dogs, and a narrow slip on the west side of the river Lea, which are intended to allow the rainfall to run into the Thames and the Lea respectively.

The area of the two is 1-3/4 square mile.

The area to be drained by natural outfall comprises, then, 25-1/6 square miles as regards rainfall, and the same extent as regards sewage; while the area to the drainage of which steam power is to be applied comprises 14-1/3 square miles of rainfall, and 16-1/6 square miles of sewage; the two united areas of rainfall and sewage respectively being 39-1/2 and 41-1/3 square miles.

The length of the great “high-level sewerage” will be, as regards the main sewer, 19 miles and 106 yards; that of the “low-level sewerage,” 14 miles and 1501 yards.

I will now describe the course of each of these constructions.

On the eastern bank of the Lea the sewage of both districts is to be concentrated. The high-level sewer will commence and _cross_ the Lea near the “Four Mills.” It is then to proceed “in a westerly direction under the East and West India Dock Railway and the Blackwall Extension Railway, beneath the Regent’s-canal, to the east end of the Bethnal-green-road, at the crossing of the Cambridge-heath-road, at which point it will be joined by the proposed northern division of the Hackney-brook, which drains an extensive district up to the watershed line north of London, including Hackney, Stoke Newington and Holloway, and part of Highgate and Hampstead; from thence the main sewer proceeds along the Bethnal-green-road, Church-street, Old-street, Wilderness-row (where a short branch from Coppice-row will join) to Brook-street-hill; from thence to Little Saffron-hill, where a distance of about 100 yards is proposed to be carried by an aqueduct over the Fleet-valley; thence along Liquorpond-street, at the end of which it will receive a branch from Piccadilly, on the south side, and a diversion of the Fleet-river, on the north side; thence along Theobald’s-road, Bloomsbury-square, Hart-street, New Oxford-street, to Rathbone-place (where it will receive a diversion of the Regent-street sewer from Park-crescent), along Oxford-street, and extending thence across Regent-circus to South Molton-lane (where it will intercept the King’s Scholars’ Pond sewer), continuing still along Oxford-street to Bayswater-place, Grand Junction-road, Uxbridge-road, where it is joined by the Ranelagh sewer, the sewage of which it is capable of receiving, and at this point it terminates.”

It is difficult to convey to a reader, especially to a reader who may not be familiar with the localities of London generally, any adequate notion of the largeness, speaking merely of extent, of this undertaking. Even a map conveys no sufficient idea of it.

Perhaps I may best be able to suggest to a reader’s mind a knowledge of this largeness, when I state that in the district I have just described, which is but _one_ portion (although the greatest) of the sewerage of but _one_ side of the Thames, more than half a million of persons, and nearly 100,000 houses are, so to speak, to be sewered.

The low-level tract sewerage, also, concentrates on the Lea, “near to Four Mill’s distillery, taking the north-western bank of the Limehouse Cut, at which point it receives the branch intended to intercept the sewage of the Isle of Dogs; thence continuing along the bank of Limehouse Cut, through a portion of the Commercial-road, Brook-street, and beneath the Sun Tavern Fields, into High-street, or Upper Shadwell; thence along Ratcliffe-highway and Upper East Smithfield, across Tower-hill, through Little and Great Tower-streets, Eastcheap, Cannon-street, Little and Great St. Thomas Apostle, Trinity-lane, Old Fish-street, and Little Knight Rider-street; thence beneath houses in Wardrobe-terrace, and on the eastern side of St. Andrew’s-hill, along Earl-street to Blackfriars-road. From Blackfriars Bridge it is proposed to construct the sewer along the river shore to the junction of the Victoria-street sewer at Percy-wharf; which sewer between Percy-wharf and Shaftesbury-terrace, Pimlico, becomes thus an integral portion of the intercepting line; at Bridge-street, Westminster, a branch from the Victoria-street sewer is intended to proceed along Abingdon and Millbank-streets, as far as and for the purpose of taking up the King’s Scholars’ Pond and other sewers at their outlets into the Thames. From Shaftesbury-terrace the Victoria-street sewer is proposed to be extended through Eaton-square and along the King’s-road, Chelsea, to Park-walk, intercepting all the sewers along its line, and terminating at a point where the drainage of Kensington may be brought into it without pumping.”

The lines of sewerage thus described are, then, all to the _west_ of the Lea, and all, whether from the shore of the Thames, or the northern reaches in Highgate and Hampstead, converging to a pumping station or sewage-concentration, on the _east_ bank of the Lea, in West Ham. By this new plan, then, the high-level sewer is to _cross_ the Lea, but that arrangement is impossible as respects the second district described, which is _below_ the level of the Lea, so that its course is to be _beneath_ that river, a little below where it is crossed by the high-level line. To dispose of the sewage, therefore, conveyed from the low-level tract, there will be a sewer of a “depth of _forty-seven_ feet _below_” the invert of the high-level sewer. This sewer, then, at the depth of 47 feet, will run to the point of concentration containing the low-level sewage.

At this point of the works, in order that the sewage may be collected, so as to be disposed of ultimately in one mass, it has to be _lifted_ from the low to the high-level sewer. The invert of the high-level sewer will at the lifting or pumping station be 20 feet _above_ the ordnance datum, while that of the low-level sewer will be 27 feet _below_ the same standard. Thus a great body of metropolitan sewage, comprising among other districts the refuse of the whole City of London, must be lifted no less than 47 feet, in order to be got rid of along with what has been carried to the same focus by its natural flow.

The lifting is to be effected by means of steam, and the pumping power required has been computed at 1100-horse power. To supply this great mechanical and scientific force, there are to be provided two engines, each of 550-horse power, with a third engine of equal capacity, to be available in case of accident, or while either of the other engines might require repairs of some duration.

The northern sewage of London (or that of the Middlesex bank of the Thames, covered by that division of the capital) having been thus brought to a sort of central reservoir, or meeting point, will be conveyed in two parallel lines of sewerage to the bank of the river Roding, being the eastern extremity of Gallion’s Reach (which is below Woolwich Reach), in the Thames. The Roding flows into the Thames at Barking Creek mouth. The length of this line will be four miles.

“At this point,” it is stated in the Report, “the level of the inverts of the parallel sewers will be eight feet below high-water mark, and here it is intended to collect the sewage into a reservoir during the flood-tide, and discharge the same with the ebb-tide immediately after high-water; and, as it is estimated that the reservoir will be completely emptied during the first three hours of the ebb, it may be safely anticipated that no portion of the sewage will be returned, with the flood-tide, to within the bounds of the metropolis.”

The whole of the sewage and rainfall, then, will be thus diverted to _one_ destination, instead of being issued into the river through a multiplicity of outlets in every part of the northern shore where the population is dense, and will be carried into the Thames at Barking Creek, unless, as I have intimated, a market be found for the sewage; when it may be disposed of as is most advantageous. The only exceptions to this carrying off will be upon the occurrence of long-continued and heavy rains or violent storms, when the surplus water will be carried off by some of the present outlets into the river; but even on such occasions, the _first scour_ or cleansings of the sewerage will be conveyed to the main outlet at the river Roding.

The inclination which has been assigned to the whole of the lines of sewers I have described, is, with some unimportant exceptions, 4 feet per mile, or 1 in 1320. These new sewers are, or rather will be, calculated to carry off a fall of rain, equal to 1/4 inch in 24 hours, in addition to the average daily flow of sewage.

Mr. Forster concludes his Report:--“I am only able to submit approximately that I estimate the cost of the whole of the lines of sewers, the pumping engines, and station, the reservoir, tidal gates, and other apparatus, at one million and eighty thousand pounds (1,080,000_l._). This estimate does not include the sums required for the purchase of land and houses, which may be needed for the site of the pumping engine-house, or compensation for certain portions of the lines of sewers.”

As regards the improvements in the sewerage on the south side of the Thames (the great fever district of the metropolis, and consequently the most important of all, and where the drainage is of the worst kind), I can be very brief, as nothing has been positively determined.